OPACIFIER CONCENTRATE AND ITS USE TO MODIFY THE APPEARANCE AND/OR INCREASE OPACITY AND/OR WHITENESS OF AN AQUEOUS COMPOSITION

Abstract

The present invention relates to a sulfate-free aqueous concentrate comprising at least: (i) at least 25% by weight of opacifier particles selected from C16-C22 fatty acid, C16-C22 fatty alcohol, mono-, di- and tri-C16-C22 esters of glycerol, mono- and di-C16-C22 esters of ethylene glycol, diethylene glycol and triethylene glycol, C16-C22 fatty acid alkanolamides and mixtures thereof, with said particles are having a median diameter ranging from 1 to 15 μm; (ii) an amphoteric or zwitterionic surfactant, (iii) water, with the total amount of surfactants in said aqueous concentrate ranging from 0.5 to 15% by weight, relative to the total weight of the aqueous concentrate. It also relates to the use of such an aqueous concentrate as an opacifier. The aqueous concentrate of the invention may be used as an opacifier in a composition, to replace at least some of a styrene opacifier or titanium dioxide in said composition.

Claims

1. A sulfate-free aqueous concentrate comprising at least: i) at least 25% by weight of opacifier particles selected from C16-C22 fatty acid, C16-C22 fatty alcohol, mono-, di- and tri-C16-C22 esters of glycerol, mono- and di-C16-C22 esters of ethylene glycol, diethylene glycol and triethylene glycol, C16-C22 fatty acid alkanolamides and mixtures thereof, with said particles are having a median diameter measured by laser diffraction ranging from 1 to 15 μm; ii) an amphoteric or zwitterionic surfactant, iii) water, with the total amount of surfactants in said aqueous concentrate ranging from 0.5 to 15% by weight, relative to the total weight of the aqueous concentrate.

2. The aqueous concentrate according to anyone of the preceding claims, wherein said opacifier particles are mono- or di-C16-C22 esters of ethylene glycol and mixtures thereof, for instance ethylene glycol distearate.

3. The aqueous concentrate according to anyone of the preceding claims, wherein said opacifier particles have a median diameter lower than 14 μm, for instance lower than 12 μm and/or greater than 2 μm, for instance greater than 4 μm.

4. The aqueous concentrate according to anyone of the preceding claims, containing at least 30% by weight, for example from 30 to 75% by weight, for example from 30 to 60% by weight, for example from 30 to 50% by weight of said opacifier particles, relative to the total weight of the aqueous concentrate.

5. The aqueous concentrate according to anyone of the preceding claims, containing less than 15% by weight, for example from 0.1 to 15% by weight, for example from 0.5 to 15% by weight, for example from 1 to 10% by weight of said surfactant, relative to the total weight of the aqueous concentrate.

6. The aqueous concentrate according to anyone of the preceding claims, containing at least 20% by weight, for example from 20 to 60% by weight, for example at least 30% by weight, for example at least 40% by weight, for example from 40 to 60% by weight of water, relative to the total weight of the aqueous concentrate.

7. The aqueous concentrate according to anyone of the preceding claims, containing amphoteric or zwitterionic surfactants in an amount ranging from 0.5 to 15% by weight, especially from 1 to 10% by weight, for instance from 4 to 8% by weight, relative to the total weight of the aqueous concentrate.

8. The aqueous concentrate according to anyone of the preceding claims, containing from 0 to less than 2% by weight of non ionic surfactant relative to the total weight of the aqueous concentrate.

9. The aqueous concentrate according to anyone of the preceding claims, containing from 0 to less than 2% by weight of anionic surfactant relative to the total weight of the aqueous concentrate

10. The aqueous concentrate according to anyone of the preceding claims, containing from 0 to less than 2% by weight of emollient, such as for instance glyceryl oleate, relative to the total weight of the aqueous concentrate.

11. Use of the aqueous concentrate of claim 1 as an opacifier.

12. A method for modifying the appearance of a composition, comprising adding an aqueous concentrate according to claim 1 to such composition.

13. A method to increase the opacity and/or whiteness of a composition, comprising adding an aqueous concentrate according to claim 1 to such composition.

14. A composition comprising from 1 to 5% by weight of the aqueous concentrate of claim 1, relative to the total weight of the composition.

15. The composition of claim 14, further containing a colouring agent.

Description

EXAMPLES

Example 1: Preparation of Aqueous Concentrates in Accordance with the Invention

Example 1a: Preparation of Aqueous Concentrate A

[0173] An aqueous concentrate of the invention (Aqueous concentrate A) has been prepared according to the following procedure.

[0174] 34.5 wt % of Ethylene glycol distearate (Mackester GDSV flakes, available from Solvay), 34.5 wt % of water, and 7.7 wt % of Cocamidopropyl Betaine (Mackam 35, available from Solvay) are added together into a grinding pot.

[0175] This mixture is mixed with a high shear Cowles blade at 700 RPM until the coarse slurry is transformed into a smooth flowing fluid with viscosity between 350 and 450 cP. Cooling is applied to the grinding pot to maintain the temperature below 15° C., under stirring with an agitator.

[0176] The slurry is then pumped through an horizontal mill (temperature maintained below 35° C. exiting the mill).

[0177] 14.2 wt % of Cocamidopropyl Betaine (Mackam 35, available from Solvay) and 8.4 wt % of water are added to the milled concentrate. The pH is adjusted to about 4.8 by adding Citric Acid. The solids level is measured using a moisture balance to determine if additional water is needed to reach a final solids content of about 46%.

[0178] Aqueous concentrate A is a white liquid at room temperature that does not exhibit pearl shine.

[0179] It has a melting point, measured according to the protocole of the description, greater than 50° C.

Example 1b: Preparation of Aqueous Concentrate B

[0180] Another aqueous concentrate of the invention (Aqueous concentrate B) has been prepared according to the following procedure.

[0181] 45 wt % of Ethylene glycol distearate (Mackester GDSV flakes, available from Solvay), 45 wt % of water, and 10 wt % of Cocamidopropyl Betaine (Mackam CAB 818, available from Solvay) are added together into a grinding pot.

[0182] This mixture is mixed with a high shear Cowles blade at 700 RPM until the coarse slurry is transformed into a smooth flowing fluid with viscosity between 350 and 450 cP. Cooling is applied to the grinding pot to maintain the temperature below 15° C., under stirring with an agitator.

[0183] The slurry is then pumped through an horizontal mill (temperature maintained below 35° C. exiting the mill).

[0184] 14.2 wt % of Cocamidopropyl Betaine (Mackam CAB 818, available from Solvay) and 8.4 wt % of water and 0.5% of sodium Benzoate are added to the milled concentrate. The pH is adjusted to about 4.8 by adding Citric Acid. The solids level is measured using a moisture balance to determine if additional water is needed to reach a final solids content of about 42%.

[0185] Aqueous concentrate B is a white liquid at room temperature that does not exhibit pearl shine.

[0186] It has a melting point, measured according to the protocole of the description, greater than 50° C.

Example 1c: Stability Upon Storage of Aqueous Concentrate A and Aqueous Concentrate B of the Invention

[0187] Stability upon storage of aqueous concentrates A and B has also been tested according to the following temperature storage conditions:

[0188] “4° C.” means storage of the aqueous concentrate at 4° C. in a Memert ICP 450 ventilated oven.

[0189] “40° C.” means storage of the aqueous concentrate at 40° C. in a Memert IC 450 ventilated oven.

[0190] “Freeze/thaw” means submitting the aqueous concentrate to 5 freeze and thaw cycles, each cycle being composed by the following steps: decreasing the temperature from 25° C. to −9° C. in 8 hours; plateaus at −9° C. during 8 hours; increasing the temperature to reach 25° C. during 8 hours; and then plateaus at 25° C. during 8 hours.

[0191] For the “4° C.” and “40° C.” temperature storage test, viscosity is measured weekly on a Brookfield DVII+RV viscometer with a spindle rotation speed of 10 rpm.

[0192] For the “freeze/thaw” test, viscosity is measured at the end of the five cycles on a Brookfield DVII+RV viscometer with a spindle rotation speed of 10 rpm.

[0193] In each test, the appearance of the sample and its particle size (Horiba granulometer) are also assessed.

[0194] It has been established that aqueous concentrates A and B are stable at least 3 months in such temperature storage conditions (4° C., 40° C.).

[0195] It has been established that aqueous concentrates A and B are stable during 5 cycles of freeze/thaw.

Example 2

[0196] Aqueous concentrates A and B in accordance with the invention have been characterized in terms of physico-chemical properties and opacifying performances.

[0197] They have also been compared to commercially available opacifiers, namely: [0198] Mackadet® OPR1 (available from Solvay), which is an aqueous concentrate containing 15-30% by weight of ethylene glycol distearate, 1-15% by weight of glycerol monostearate, and 1-15% by weight of cocamidopropyl betaine [0199] OPULYN 301 (available from Dow), which is an anionic styrene/acrylic copolymer

[0200] Procedures:

[0201] Median Diameter

[0202] As indicated previously, particle sizes are measured by laser diffraction using laser diffraction granulometer Partica LA-960 (by HORIBA). Size distribution is given by HORIBA LA-960 particle size analyzer. This enable to determine the median diameter of the particles.

[0203] The operating conditions were the following: [0204] 30 seconds of water degassing is performed by ultrasound before adding the particles to the measuring cell. [0205] The refraction index of the degassed water was 1.33 [0206] The ethylene glycol di-stearate refraction index is 1.49. [0207] The water flow in the particle size measuring cell is 2. [0208] The water mixing speed in the particle size measuring cell is 2.

[0209] L* Whiteness and Covering Effect

[0210] As indicated previously, L* whiteness is determined using the L*a*b* colour space and covering effect is measured by the contrast card method (covering effect (expressed as a %)=(L*.sub.black background)/(L*.sub.white background)×100).

[0211] Both measurements use the spectrocolorimeter DR LANGE LUCI 100 (measuring geometry d/8° acc. to DIN 5033).

[0212] The plates that are used to measure L* whiteness consist of hexagonal shaped cells 2 cm wide by 3 mm thick. The sample quantity for each measurement is 1.5 mL per cell.

[0213] Results were the following:

TABLE-US-00001 Aqueous Aqueous concentrate A concentrate B (in accordance (in accordance Mackadet with the with the OPR1 OPULYN301 Product invention) invention) (comparative) (comparative) Aspect at room White liquid White liquid White liquid White liquid temperature (25° C.) pH 4.8 4.7 4.0-6.0 2.1-2.5 Active content (%) 46 42 41-44 about 40 Particle size (Horiba 6 to 10 μm 2 to 6 μm 16 to 20 μm <1 μm granulometer) RV Viscosity at about 200 cps about 200 cps about 7,500 cps about 200 cps 10 rpm L* whiteness 91.8 96.1 91.5 85.6 Covering effect 98% 100% 97% 92% L*.sub.black background 91.8 96.1 91.5 85.6 L*.sub.white background 93.6 96.1 94.6 93.5

[0214] Aqueous concentrate A of the invention exhibits a significantly greater L* whiteness compared to OPULYN 301.

[0215] The covering effect measured with aqueous concentrate A of the invention is also significantly greater to the one measured when using OPULYN 301.

Example 3

[0216] The performances of aqueous concentrates A and B in accordance with the invention have also been tested in a simplified personal care composition. The following base body wash composition has been prepared:

[0217] 34.35 wt % RHODAPEX® ESB 30HA1 (corresponding to 9 wt % of anionic surfactant)

[0218] 5.00 wt % Mackam® 50ULB (corresponding to 2 wt % of amphoteric surfactant)

[0219] 0.30 wt % Jaguar® Excel (corresponding to 0.3 wt % of conditioning polymer)

[0220] 0.63 wt % preservative (0.40 wt % of sodium benzoate and 0.23 wt % of salicylic acid)

[0221] 1.60 wt % NaCl (salts)

[0222] 0.50 wt % of citric acid 50% (corresponding to 0.25 wt % of pH adjuster)

[0223] Balance Water

[0224] To this base body wash composition has been added an opacifier, which was aqueous concentrate A (in accordance with the invention), aqueous concentrate B (in accordance with the invention), Mackadet® OPR1 (comparative) or OPULYN 301 (comparative).

[0225] Preparation process was the following

[0226] In a plastic beaker, the ingredients are added in the following order.

[0227] First, the conditioning polymer is added in water. When it is fully hydrated, then the amphoteric surfactant is added in the main vessel under mechanical stirring (Heidolph RZR2021) with a paddle blade. The anionic surfactant is added afterwards and pH is then adjusted between 4.8 to 5 with the diluted citric acid solution (50% in weight). Preservative (sodium benzoate an salicylic acid) are then added, followed by salts (sodium chloride).

[0228] The blend is stirred until an homogeneous mixture is obtained.

[0229] To this base body wash composition is then added the opacifier (aqueous concentrate A, or aqueous concentrate B, or Mackadet® OPR1, or OPULYN 301), in an amount of about 1.8% (active material).

[0230] The mixture is stirred to obtain a fully opaque and homogeneous solution. pH is adjusted to 4.8-5 with citric acid if need be.

[0231] Covering effect and stability upon storage of the corresponding formulations have been tested according to the procedures described previously in Example 1 and 2.

[0232] Results were the following:

TABLE-US-00002 Aqueous Aqueous concentrate A concentrate B (in accordance (in accordance Mackadet with the with the OPR1 OPULYN301 Product invention) invention) (comparative) (comparative) Dosage in 1.8 1.8 1.8 0.4 formulation (% in active) pH 4.8 4.8 4.8 4.8 RV Viscosity at 4260 7060 3160 1180 10 rpm (mPa .Math. s.sup.−1) L* whiteness 59.5 65.5 36.5 37.9 Covering effect 74% 79.6% 47.6% 47.9% L*.sub.black background 59.5 65.5 36.5 37.9 L*.sub.white background 80.5 82.3 76.7 79.2 Temperature Stable 3 month Stable 3 month Stable 3 month Stable 3 month storage stability in temperature in temperature in temperature in temperature (4° C., 40° C., storage storage storage storage freeze/thaw)

[0233] A personal care composition containing an aqueous concentrate of the invention (aqueous concentrate A or B) exhibits a significantly greater covering effect compared to an identical personal care composition containing either Mackadet OPR1 or OPULYN 301 as opacifier.

[0234] A personal care composition containing an aqueous concentrate of the invention (aqueous concentrate A or B) exhibits a significantly greater Whiteness compared to an identical personal care composition containing either Mackadet OPR1 or OPULYN 301 as opacifier.

Example 4

[0235] In order to illustrate the advantageous high flexibility of the aqueous concentrate of the invention, the following comparative experiment has been carried out.

[0236] In a simplified personal care composition, an aqueous concentrate of the invention (Aqueous concentrate A, see Example 1a, in an amount corresponding to 1.8% in active) has been added directly “as is” in order to modify its appearance (in particular increase its opacity).

[0237] As can be seen on FIG. 1 (composition on the left side), the opacifier particles are readily incorporated into the existing end-use formulation. The resulting formulation is homogeneous.

[0238] The same experiment has been conducting using a comparative prior art aqueous concentrate (OPULYN 301, as described previously, in an amount corresponding to 0.4% in active). This comparative aqueous concentrate has also been added directly “as is” in identical relative amount in the same simplified personal care composition.

[0239] As can be seen on FIG. 1 (composition on the right side), in this case there is some sedimentation of the opacifier particles. The resulting formulation is not homogeneous. In contrast, part of the opacifier particles tends to deposit on the walls.

[0240] This confirm that the opacifier particles of the invention may be readily added into aqueous compositions without any constraints as regards existing manufacturing processes, providing a high flexibility.

[0241] Advantageously, aqueous concentrate of the invention may be easily added for example “on top”, namely directly “as is” at the end of the manufacturing process.

[0242] The aqueous concentrate of the invention is provided in a liquid form that can be readily used: there is no need to make any premix formulation beforehand.

[0243] Also, compared to liquid kaolin-based concentrates of the prior art, the aqueous concentrate of the invention advantageously does not require the presence of rheological agents, or the like, in the final end-use formulation.

[0244] This is particularly important in personal care formulation, since such additional rheological agents may negatively impact attributes of said end-use formulation, such as flash foam or sensorial experience.

Example 5

[0245] In order to illustrate the advantageous impact on color intensity of the aqueous concentrate of the invention when added into a coloured composition, the following comparative experiments have been carried out.

[0246] The following coloured shampoo compositions have been prepared:

[0247] 43.56 wt % RHODAPEX® ESB 30HA1 (corresponding to 11.4 wt % of anionic surfactant)

[0248] 6.20 wt % of colouring agent

[0249] 5.00 wt % Mackam® 50ULB (corresponding to 2 wt % of amphoteric surfactant)

[0250] 1 wt % opacifier agent (active ingredient)

[0251] 0.30 wt % Jaguar® Excel (corresponding to 0.3 wt % of conditioning polymer)

[0252] 0.63 wt % preservative (0.40 wt % of sodium benzoate and 0.23 wt % of salicylic acid)

[0253] 1.60 wt % NaCl (salts)

[0254] 0.60 wt % of citric acid 50% (corresponding to 0.25 wt % of pH adjuster)

[0255] Balance of Water

[0256] Using 4 different colouring agents (=colouring agent i-iv), a total of 8 coloured shampoo compositions were prepared, namely: [0257] 4 compositions including the aqueous concentrate A of the invention (see Example 1) (=“composition of the invention”) and one colouring agent chosen from colouring agent i-iv (=composition i, ii, iii or iv respectively) and [0258] 4 comparative compositions including prior art OPULYN 301 (=“comparative composition”) and one colouring agent chosen from colouring agent i-iv (=composition i, ii, iii or iv respectively)

[0259] The colouring agents used in each composition were the following: [0260] In composition i: colouring agent=Unicert Violet K7025-J (used in the form of a solution in water at 0.2 wt % of dye) [0261] In composition ii: colouring agent=Unicert Rouge K7057-J (used in the form of a solution in water at 0.2 wt % of dye) [0262] In composition iii: colouring agent=Unicert Rouge 07004-J (used in the form of a solution in water at 0.2 wt % of dye) [0263] In composition iv: colouring agent=Sensient Vert menthe E C0597 (used in the form of a solution in water at 1.0 wt % of dye)

[0264] Results can be shown on FIGS. 2-5 showing respectively:

[0265] FIG. 2: Compositions (i) containing Unicert Violet K7025-J as colouring agent and either the aqueous concentrate A of the invention (composition of the invention on the left side) or OPULYN 301 (comparative composition on the right side)

[0266] FIG. 3: Compositions (ii) containing Unicert Rouge K7057-J as colouring agent and either the aqueous concentrate A of the invention (composition of the invention on the left side) or OPULYN 301 (comparative composition on the right side)

[0267] FIG. 4: Compositions (iii) containing Unicert Rouge 07004-J as colouring agent and either the aqueous concentrate A of the invention (composition of the invention on the left side) or OPULYN 301 (comparative composition on the right side)

[0268] FIG. 5: Compositions (iv) containing Sensient Vert menthe E C0597 as colouring agent and either the aqueous concentrate A of the invention (composition of the invention on the left side) or OPULYN 301 (comparative composition on the right side)

[0269] As can be seen on FIGS. 2-5, at iso dose of opacifier particles and whatever the colouring agent, it is visible to the naked eye that a composition of the invention containing the aqueous concentrate A of the invention yields to coloured shampoo compositions that are more intense and more colored compared to comparative compositions containing Opulyn 301.

[0270] This demonstrates the benefits in using the aqueous concentrate A of the invention in coloured compositions.

[0271] Advantageously, the opacifier concentrates of the invention also do not negatively impact color shade.

[0272] Given the specific and improved whiteness of the opacifier concentrates of the invention, coloured compositions containing them do not exhibit greying or blueing effect. This is critical when compared for instance with coloured compositions including Opulyn 301.

Example 6

[0273] The performances of aqueous concentrate B in accordance with the invention has also been tested in an oral care composition.

[0274] The following oral care composition (toothpaste chassis) has been prepared (in this example, the amounts correspond of the wt % of the product as is):

[0275] 0.4 wt % of carboxymethyl cellulose (CMC)

[0276] 45 wt % of sorbitol

[0277] 5 wt % of PEG 600

[0278] 0.8 of wt % sodium fluoride

[0279] 0.2 wt % of sodium saccharin

[0280] 10 wt % of Tixosil 63

[0281] 8.5 wt % of Tixosil 43

[0282] 0.5 wt % of titanium dioxide

[0283] 2-5 wt % of surfactants

[0284] Flavor

[0285] Opacifier (either TiO2 or Aqueous Concentrate B of the invention)

[0286] Balance of Water

[0287] These formulations have been prepared according to the following procedure: [0288] Prepare a dispersion of CMC in PEG and sorbitol under mixing. Add CMC very slowly, allowing it to fully incorporate before adding water phase. [0289] Prepare a premix of Sodium Fluoride, Sodium Saccharin, and opacifier (either TiO2 or Aqueous Concentrate B of the invention) in Water. Add premix to main batch and mix well. [0290] Add the Tixosil slowly into the main batch under constant mixing. [0291] Add flavor, surfactant and mix slowly until homogenous.

[0292] A total of 3 compositions were prepared, using as opacifier either TiO2 (added at 0.5 wt % as is) or an aqueous concentrate of the invention (added respectively at 2 or 4% wt as is).

[0293] Results can be shown on FIG. 6 showing respectively toothpaste compositions containing aqueous concentrate B of the invention at 2 wt % (on the left side) and at 4 wt % (center) or TiO2 at 0.5 wt % (comparative composition on the right side).

[0294] When observed in the bulk, performances of the aqueous concentrate of the invention both in terms of opacity and whiteness are visible to the naked eye.

Example 7

[0295] The performances of aqueous concentrate B have also been tested in a simplified Home care composition.

[0296] The following base Hand dish liquid composition has been prepared:

[0297] 24.28 wt % RHODAPEX® ESB 70 (corresponding to l7 wt % of anionic surfactant)

[0298] 6 wt % Mackam® 50ULB (corresponding to 2.4 wt % of amphoteric surfactant)

[0299] 4.44 wt % Mackamine CAO E 36 (corresponding to 1.6% of non ionic surfactants)

[0300] 0.1 wt % preservative (0.1% Methylisothiazolinone/methyl chloro thiazolinone)

[0301] 0.6 wt % NaCl (salts)

[0302] Balance of Water

[0303] To this base Hand Dish liquid composition has been added an opacifier, which was aqueous concentrate B in accordance with the invention.

[0304] Preparation process was the following: in a beaker, weight water and then all ingredients in a beaker and mix well until homogeneisation. To this base body wash composition is then added the opacifier (aqueous concentrate B), in an amount of 1.0% (active material). The mixture is stirred to obtain a fully opaque and homogeneous solution.

[0305] Covering effect of the corresponding formulations have been tested according to the procedures described previously in Example 1 and 2.

[0306] Results were the following:

TABLE-US-00003 Aqueous concentrate B Product (in accordance with the invention) Dosage in formulation (% in active) 1.0 L* whiteness 47.7 Covering effect 60.9 L*.sub.black background 47.7 L*.sub.white background 78.4

[0307] A Home care composition containing the aqueous concentrate B of the invention exhibits improved covering effect and whiteness.